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. 2020 Mar 10;8:40. doi: 10.3389/fpubh.2020.00040

Table 3.

Serotype distribution (total number of isolates received) and resistance to erythromycin (Ery) and clindamycin (Cli) among invasive Streptococcus agalactiae (GBS) isolates received at Statens Serum Institut (SSI), 2005–2018.

Serotype Number of isolates 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Total %a,b P-value (Z score)c/r (95% CI) and P-valued
Ia Total 15 15 15 18 24 19 27 26 23 22 25 25 30 24 308 16.4 P = 0.69 (0.49)c
Ery 1 2 1 1 4 4 7 3 4 5 10 6 5 6 59 19.2 r = 0.74 (0.32–0.91)
P = 0.004d*
Cli 0 1 1 0 1 0 1 1 1 0 2 0 2 4 14 4.5 r = 0.47 (−0.10–0.81)
P = 0.09d
Ib Total 14 15 9 17 10 15 7 14 16 5 15 17 15 13 182 9.7 P = 0.99 (2.52)c
Ery 1 0 1 2 0 0 0 2 2 0 1 1 1 2 13 7.1 r = 0.42 (−0.16–0.78)
P = 0.13d
Cli 1 0 1 1 0 0 0 2 1 0 1 1 1 2 11 6.0 r = 0.26 (−0.33–0.70)
P = 0.37d
II Total 9 7 4 9 21 9 17 11 11 20 20 18 16 24 196 10.5 P = 0.04 (−1.74)c*
Ery 0 1 0 2 4 4 2 2 2 6 5 4 2 6 40 20.4 r = 0.83 (0.52–0.95)
P = 0.0004d*
Cli 0 1 0 2 5 4 2 3 1 6 5 4 1 6 40 20.4 r = 0.81 (0.48–0.94)
P = 0.0007d*
III Total 18 31 32 53 48 39 37 36 39 48 36 45 42 51 555 29.6 P = 0.98 (2.08)c
Ery 3 2 1 3 5 8 7 4 11 11 8 15 9 11 98 17.7 r = 0.54 (−0.01–0.84)
P = 0.0487d
Cli 3 1 2 5 7 7 7 3 10 8 8 15 9 11 96 17.3 r = 0.60 (0.08–0.86)
P = 0.0261d*
IV Total 4 6 4 6 1 6 7 6 6 10 6 10 5 10 87 4.6 P = 0.35 (−0.39)c
Ery 2 0 0 0 0 1 0 0 0 3 0 0 0 3 9 10.3 r = 0.32 (−0.27–0.74)
P = 0.27d
Cli 2 0 0 0 0 1 0 0 0 3 0 0 0 2 8 9.2 r = 0.29 (−0.30–0.72)
P = 0.31d
V Total 15 10 21 15 17 17 13 14 12 13 19 34 20 33 253 13.5 P = 0.31 (−0.48)c
Ery 1 2 3 10 9 6 6 5 1 2 2 6 6 5 64 25.3 r = 0.36 (−0.22–0.76)
P = 0.20d
Cli 1 2 3 8 9 6 6 5 2 1 2 5 6 4 60 23.7 r = 0.27 (−0.32–0.71)
P = 0.35d
VI Total 0 0 0 0 4 0 0 2 2 0 3 2 0 4 17 0.9 P = 0.055 (−1.60)c
Ery 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
Cli 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
VII Total 0 0 1 0 0 1 0 0 1 0 0 1 0 0 4 0.2 P = 0.65 (0.40)c
Ery 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
Cli 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
VIII Total 1 2 0 3 1 2 3 5 3 3 3 6 6 9 47 2.5 P = 0.004 (−2.66)c*
Ery 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 2.1 r = −0.21 (−0.68–0.37)
P = 0.64d
Cli 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 2.1 r = −0.21 (−0.68–0.37)
P = 0.64d
IX Total 2 0 4 2 1 0 1 2 0 6 2 9 3 7 39 2.1 P = 0.01 (−2.19)c*
Ery 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
Cli 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Not applicable
NT Total 6 6 9 7 15 22 17 10 18 16 8 14 13 26 187 9.8 P = 0.22 (−0.76)c
Ery 1 0 2 2 9 8 4 1 3 4 3 2 1 5 45 24.1 r = 0.85 (0.57–0.95)
P = 0.0002d*
Cli 1 0 1 2 7 6 5 1 3 1 3 2 2 2 36 19.3 r = 0.82 (0.50–0.94)
P = 0.0006d*
Total Total 84 92 99 130 142 130 129 126 131 143 137 181 150 201 1875 100.0
Ery 9 8 8 20 31 31 26 17 23 31 29 34 24 38 329 17.5 P = 0.011 (−2.29)c*
Cli 8 6 8 18 29 24 21 15 18 19 21 27 21 31 266 14.2 P = 0.09 (−1.36)c

The clindamycin data include the inducible clindamycin resistance isolates.

a

The total % represents percentage of a specific serotype vs. total number of isolates.

b

The % of resistant (Ery, Cli) serotype specific isolates vs. total number of serotype specific isolates.

c

Asymptotic Cochran–Armitage trend test P-value (Z-score).

d

Spearman r correlation with 95% CI (lower CI; upper CI) and P-value, measuring the correlation between the total number of isolates and the resistance isolates.

*

Value is statistically significant if P < 0.05.